Editing Electroplating (section)

=== Cleanliness ===
[[Parts cleaning|Cleanliness]] is essential to successful electroplating, since molecular layers of [[oil]] can prevent adhesion of the coating. [[ASTM]] B322 is a standard guide for cleaning metals prior to electroplating. Cleaning includes solvent cleaning, hot alkaline detergent cleaning, electrocleaning, [[ultrasonic cleaning]] and acid treatment. The most common industrial test for cleanliness is the waterbreak test, in which the surface is thoroughly rinsed and held vertical. [[Hydrophobic]] contaminants such as oils cause the water to bead and break up, allowing the water to drain rapidly. Perfectly clean metal surfaces are [[hydrophilic]] and will retain an unbroken sheet of water that does not bead up or drain off. ASTM F22 describes a version of this test. This test does not detect hydrophilic contaminants, but electroplating can displace these easily, since the solutions are water-based. [[Surfactant]]s such as [[soap]] reduce the sensitivity of the test and must be thoroughly rinsed off.